Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932788AbbG1Jva (ORCPT ); Tue, 28 Jul 2015 05:51:30 -0400 Received: from mail-wi0-f170.google.com ([209.85.212.170]:37360 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755358AbbG1Jpn (ORCPT ); Tue, 28 Jul 2015 05:45:43 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nikolay Aleksandrov , "David S. Miller" , Jiri Slaby Subject: [PATCH 3.12 077/124] bridge: fix multicast router rlist endless loop Date: Tue, 28 Jul 2015 11:43:31 +0200 Message-Id: X-Mailer: git-send-email 2.4.6 In-Reply-To: <90d8a5681e4a9e320611b422f0ed012e148c2bca.1438076484.git.jslaby@suse.cz> References: <90d8a5681e4a9e320611b422f0ed012e148c2bca.1438076484.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2278 Lines: 66 From: Nikolay Aleksandrov 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 1a040eaca1a22f8da8285ceda6b5e4a2cb704867 ] Since the addition of sysfs multicast router support if one set multicast_router to "2" more than once, then the port would be added to the hlist every time and could end up linking to itself and thus causing an endless loop for rlist walkers. So to reproduce just do: echo 2 > multicast_router; echo 2 > multicast_router; in a bridge port and let some igmp traffic flow, for me it hangs up in br_multicast_flood(). Fix this by adding a check in br_multicast_add_router() if the port is already linked. The reason this didn't happen before the addition of multicast_router sysfs entries is because there's a !hlist_unhashed check that prevents it. Signed-off-by: Nikolay Aleksandrov Fixes: 0909e11758bd ("bridge: Add multicast_router sysfs entries") Acked-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/bridge/br_multicast.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index b11736ad2e0b..f2c104900163 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1088,6 +1088,9 @@ static void br_multicast_add_router(struct net_bridge *br, struct net_bridge_port *p; struct hlist_node *slot = NULL; + if (!hlist_unhashed(&port->rlist)) + return; + hlist_for_each_entry(p, &br->router_list, rlist) { if ((unsigned long) port >= (unsigned long) p) break; @@ -1115,12 +1118,8 @@ static void br_multicast_mark_router(struct net_bridge *br, if (port->multicast_router != 1) return; - if (!hlist_unhashed(&port->rlist)) - goto timer; - br_multicast_add_router(br, port); -timer: mod_timer(&port->multicast_router_timer, now + br->multicast_querier_interval); } -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/